Zephyr API to read the nRF5340 die temperature

[Learner]

Hello,

I am looking for some some nRF5340 example code that reads the nRF5340 die temperature using zephyr APIs.

I've looked at previous posts but I could only find this one https://devzone.nordicsemi.com/f/nordic-q-a/56171/how-to-get-die-temperature-on-nrf52832-using-zephyr from 10 months ago that stated none existed. I am hoping someone, somewhere musty have done something similar.

Thank you.

Kind regards

[Håkon Alseth]

Hi,

 

The temp peripheral is only accessible on the network core:

https://infocenter.nordicsemi.com/topic/ps_nrf5340/temp.html?cp=3_0_0_6_33

So we need to configure the board nrf5340pdk_nrf5340_cpunet, but since the network core is started from the app cpu, you first need to have something on the app core running with this config set:

CONFIG_BOARD_ENABLE_CPUNET=y

 

I used sample/nrf5340/empty_app_core.

 

For uart output from the network core, connect P0.25 to P0.20.

If you also need UART RXD, connect P0.26 to P0.22.

 

Here's an example that shows how to use the NRF_TEMP peripheral: 

0677.nrf_temp_sample.zip

 

Kind regards,

Håkon

[Learner]

Hi Hakon,

I have built and run the project that reads the die temperature. I can see the see the temperature values going up and down as I heat and cool the device. However, I am still not clear how to read these values from the network core into my application. 

Please advise.

Kind regards

Mohamed

[Håkon Alseth]

Hi Mohamed,

 

Learner said:

&temp {
compatible = "nordic,nrf-temp";
status = "okay";
};

Learner said:

-- Board: nrf5340pdk_nrf5340_cpuapp

Could you confirm if the nrf5340pdk_nrf5340_cpuapp.overlay contains "temp"?

The TEMP peripheral is only available on the network core. The reason why you are getting an error is because for this specific board, there is no "temp" component.  

 

Kind regards,

Håkon

[Learner]

Hi Hakon,

I forgot to include details of the error I am getting in SES. Here it is below,

Creating solution spi_test_LR1110-2-TX-RX-CMAC-AES.emProject
C:/Zypher/v1.5.0-rc1/toolchain/opt/bin/cmake.exe -GNinja -DBOARD=nrf5340pdk_nrf5340_cpuapp -DBOARD_DIR=C:\Zypher\v1.5.0-rc1\zephyr\boards\arm\nrf5340dk_nrf5340 -BC:\Dev\PID-4\spi_test_LR1110-2-TX-RX-CMAC-AES\build_nrf5340pdk_nrf5340_cpuapp_Zypher_v1.50rc1_temp -SC:\Dev\PID-4\spi_test_LR1110-2-TX-RX-CMAC-AES -DNCS_TOOLCHAIN_VERSION=1.5.0 -DDTC_OVERLAY_FILE=C:\Dev\PID-4\spi_test_LR1110-2-TX-RX-CMAC-AES/nrf5340pdk_nrf5340_cpuapp.overlay -DEXTRA_KCONFIG_TARGETS=menuconfig_ses -DEXTRA_KCONFIG_TARGET_COMMAND_FOR_menuconfig_ses=C:\Zypher\v1.5.0-rc1\toolchain\segger_embedded_studio/html/configure_nordic_project_menuconfig.py
-- Application: C:/Dev/PID-4/spi_test_LR1110-2-TX-RX-CMAC-AES
-- Zephyr version: 2.4.99 (C:/Zypher/v1.5.0-rc1/zephyr)
-- Found Python3: C:/Zypher/v1.5.0-rc1/toolchain/opt/bin/python.exe (found suitable exact version "3.8.2") found components: Interpreter
-- Found west (found suitable version "0.9.0", minimum required is "0.7.1")
-- Board: nrf5340pdk_nrf5340_cpuapp
-- Cache files will be written to: C:/Zypher/v1.5.0-rc1/zephyr/.cache
-- Found dtc: C:/Zypher/v1.5.0-rc1/toolchain/opt/bin/dtc.exe (found suitable version "1.4.7", minimum required is "1.4.6")
-- Found toolchain: gnuarmemb (C:/Zypher/v1.5.0-rc1/toolchain/opt)
-- Found BOARD.dts: C:/Zypher/v1.5.0-rc1/zephyr/boards/arm/nrf5340dk_nrf5340/nrf5340pdk_nrf5340_cpuapp.dts
-- Found devicetree overlay: C:/Dev/PID-4/spi_test_LR1110-2-TX-RX-CMAC-AES/nrf5340pdk_nrf5340_cpuapp.overlay
-- Configuring incomplete, errors occurred!
Including boilerplate (Zephyr base): C:/Zypher/v1.5.0-rc1/zephyr/cmake/app/boilerplate.cmake
-- Using NCS Toolchain 1.5.0 for building. (C:/Zypher/v1.5.0-rc1/toolchain/cmake)
Error: nrf5340pdk_nrf5340_cpuapp.dts.pre.tmp:710.1-6 Label or path temp not found
FATAL ERROR: Syntax error parsing input tree
CMake Error at C:/Zypher/v1.5.0-rc1/zephyr/cmake/dts.cmake:205 (message):
command failed with return code: 1
Call Stack (most recent call first):
C:/Zypher/v1.5.0-rc1/zephyr/cmake/app/boilerplate.cmake:533 (include)
C:/Zypher/v1.5.0-rc1/zephyr/share/zephyr-package/cmake/ZephyrConfig.cmake:24 (include)
C:/Zypher/v1.5.0-rc1/zephyr/share/zephyr-package/cmake/ZephyrConfig.cmake:35 (include_boilerplate)
CMakeLists.txt:14 (find_package)

error: cmake failed
create_nordic_project.py failed (1)

Håkon Alseth said:

Could you confirm if the nrf5340pdk_nrf5340_cpuapp.overlay contains "temp"?

Yes, I confirm my overlay file nrf5340pdk_nrf5340_cpuapp.overlay does contain  the "temp", because your blinky example appcore overlay file also contains it. The only difference I called my overlay file *_cpuapp.overlay while you called yours *_cpunet.overlay. Why and what is the significance of the naming convention?

&temp {
 compatible = "nordic,nrf-temp";
 status = "okay";
};

Håkon Alseth said:

The TEMP peripheral is only available on the network core.

But in the example you sent me, in the blinky_appcore project you have an overlay file called nrf5340pdk_nrf5340_cpunet.overlay and contains "temp" which suggests that board nrf5340pdk does have a temp component. In fact your example ran, read and printed temperature values.

Why is the appcore overlay file labelled "cpunet" when it is on the appcore?

 

Kind regards

Mohamed

[Håkon Alseth]

Hi, 

 

Learner said:

Yes, I confirm my overlay file nrf5340pdk_nrf5340_cpuapp.overlay does contain  the "temp", because your blinky example appcore overlay file also contains it. The only difference I called my overlay file *_cpuapp.overlay while you called yours *_cpunet.overlay. Why and what is the significance of the naming convention?

the project will only pick up the overlay file if it matches the board you've selected.

You can have several other .overlay files, but they will not be picked up unless you either specify them explicitly or that they match the same board as you configure for.

 

Example: If you configure the project for board nrf52840dk_nrf52840, it will look for "nrf52840dk_nrf52840.overlay".

 

Learner said:

But in the example you sent me, in the blinky_appcore project you have an overlay file called nrf5340pdk_nrf5340_cpunet.overlay and contains "temp" which suggests that board nrf5340pdk does have a temp component. In fact your example ran, read and printed temperature values.

I should have deleted that file from that specific folder to avoid confusion, my apologies. That file was not included when you configured for nrf5340pdk_nrf5340_cpuapp, as it does not match the current board you were selecting. If you look at the product specification, the application core does not have access to the temp peripheral.

 

Kind regards,

Håkon 

[Learner]

Hi Hakon,

First, can you please get someone to look at why I cannot reply to your latest response because there is no "Reply" button to click on.

Håkon Alseth said:

I should have deleted that file from that specific folder to avoid confusion, my apologies.

I think this is the root cause of my problems.

Håkon Alseth said:

That file was not included when you configured for nrf5340pdk_nrf5340_cpuapp, as it does not match the current board you were selecting.

My overlay file is nrf5340pdk_nrf5340_cpuapp.overlay and contains "temp" and my board is nrf5340pdk_nrf5340_cpuapp, so in my case my overlay file was included hence the error I am seeing.

So, the solution to the problem I am seeing is NOT to have "temp" in my overlay file in the _appcore project. I will delete any reference to "temp" in my overlay file I have in my *_appcore project and see if this solves the problem. I will update you shortly.

Kind regards

Mohamed

[Devin Li]

I tested this code and found that after opening the net core RTT log, the app core serial terminal can output the temp value. If close the RTT window and reset 5340 DK, the log in the serial terminal stops at the "App core" and no temp value is output, why is this?

Best regards,
Devin